The Portadown undertaker had a mountain to climb to overturn Sinn Fein's 15,000-plus majority established by Martin McGuinness in 2010 – but his backers were pleased with his performance.

Mr Lutton said: "I must say I feel very humbled. I was really not expecting the result to be as good as this.

"I think it shows that the parties can work together and that people will come out in support, because unionism needs to stop beating itself."

But asked if he will now consider running for the Assembly or in next year's council elections, Mr Lutton declined to comment.

A senior Ulster Unionist said: "It would seem to have worked to the extent that people who have not voted for a while, or have not voted before, have come out this time. But that has to be held against those who did not vote for whatever reason."

North Belfast, Fermanagh & South Tyrone and Upper Bann have emerged as potential constituencies in which joint candidates could emerge for the next general election.

Ulster Unionist Mike Nesbitt, who was at the Cookstown count last night, declined to comment, but said both parties would want to analyse the results.

DUP leader Peter Robinson has already made clear that future joint candidates will prove possible, and Mr Nesbitt has refused to rule it out.